Chicago motor

What was "The Chicago Motor"?

A J/JD with the sparkplugs closer to the combustionchamber...
I think, Stéph

Steph,
Yer gettin there. More specifics needed.

motor named after a race trac

The track was at Chicago and a new 100mile record...
Stéph

Steph,
You are dancin all around it. What year? What was the big change in the engine? Wht wasn't it added to the line?

1915 ....7fins and iff you have a set or iff you know somebody who wants to sell or change a set I'm interested!!!
Stéph

1915 is correct. What was the change, why didn't it make it into production models?

No sparkplugs good enough at the time,to do the job this close to the combustion?
Stéph

Steph,
The spark plugs wern't near the combustion chamber, they were in it. The bikes ran great but the spark pluges disenergrated.

There's a Chicago cyl on Ebay 300054669295 the guy doesn't want to sell outside US
Stéph

Steph,
Those are not Chicago cylinders. They are common JD cylinders.

Chris take a good look at the rusted one and the sparkplug position compared to the other...or compare it with the pics in Hatfields book.
Stéph

Steph. I took a good lok at both of them. They both have the spark plug hole in the precombustion chamber. Look on page 25 in Hatfield's book for a photo of the Chicago cylinder. The one pictured on eBay can be found on page 51.

Thanks Chris I probably got carried away by hope...
Stéph